A diamond tool device

Abstract

The present invention belongs to the technical field of ultra-precision cutting, and specifically relates to a diamond tool device. It includes: a diamond tool, a tool holder, wherein the diamond tool has: an electrode; a boron-doped single crystal diamond layer, whose resistance changes with the temperature after being heated, and is used to sense the temperature of the cutting micro-area; and a single crystal diamond layer, which is bonded to the boron-doped single crystal diamond layer through atomic interaction; the tool holder has: a body, which is internally provided with a temperature acquisition circuit board and a power supply, an upper cover plate, and is provided with a constant current source shift button electrically connected to the temperature acquisition circuit board; the electrode is connected to the temperature acquisition circuit board through a wire, and the cutting edge of the diamond tool is arranged on the single crystal diamond layer. Since the present invention has a boron-doped single crystal diamond layer, its resistance changes with the temperature after being heated, so that the temperature of the cutting micro-area can be sensed during the working process, and can be used for online measurement of the cutting area temperature during the single-point diamond turning process.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-precision cutting and processing, and in particular relates to a diamond tool device. Background Art

[0002] Single-point diamond turning has become an important means in the field of ultra-precision machining due to its advantages of high machining accuracy, good repeatability and high machining efficiency. It is widely used in the manufacturing process of optical free surfaces (lenses, mirrors, windows, laser elements), micro-nano structure surfaces (microlens arrays, microprism arrays, compound eye microstructure arrays), precision grinding tools, etc.

[0003] The cutting process is accompanied by complex thermal-mechanical coupling interactions. Cutting temperature is an important indicator for measuring cutting conditions such as surface size, shape accuracy, cutting chatter, tool wear, etc. By sensing the cutting temperature in real time, online monitoring of the cutting state can be effectively achieved, thereby ensuring and optimizing the machining process.

[0004] At present, the commonly used online cutting temperature measurement methods are thermocouple contact and infrared non-contact. Among them, when using infrared thermal imaging to measure cutting temperature, there will be problems such as chips blocking the cutting area, the cutting temperature cannot be continuously monitored, and the spatial resolution of the infrared instrument cannot measure the cutting area temperature at the micro-nano scale. When using thin film thermocouple contact temperature measurement, there are problems such as complex sensor film preparation process, poor coating quality stability, and difficulty in controlling the insulation between the film electrode and the tool body. In addition, there is a certain distance between the two electrodes of the thin film thermocouple and the position of the diamond tool tip, which cannot meet the online measurement requirements of the quasi-cutting area temperature in precision cutting.

[0005] During the single-point diamond ultra-precision cutting process, the temperature rise of the cutting micro-area at the micro-nano cutting scale is small and changes rapidly. Therefore, there are strict requirements for the temperature measurement of the cutting area with high sensitivity, fast response speed and high spatial resolution. Therefore, it is necessary to study a device suitable for online measurement of the cutting area temperature during the single-point diamond turning process. Summary of the invention

[0006] The object of the present invention is to provide a diamond tool device, which can measure the temperature of a cutting micro-region of a target object online through a boron-doped single crystal diamond layer arranged on the diamond tool.

[0007] The present invention adopts the following technical solutions:

[0008] A diamond tool device has the following characteristics: it is used for cutting a target object and measuring the temperature of a cutting micro-region of the target object online, and comprises: a diamond tool and a tool holder for mounting the diamond tool, wherein the diamond tool comprises: an electrode; a boron-doped single crystal diamond layer, the resistance of which changes with the temperature after being heated, and is used for sensing the temperature of the cutting micro-region; and a single crystal diamond layer, which is bonded to the boron-doped single crystal diamond layer through atomic interaction; the tool holder comprises: a body, a temperature acquisition circuit board and a power supply are arranged inside, and an upper cover plate is arranged on the upper side of the body and is provided with a constant current source shift button electrically connected to the temperature acquisition circuit board; the electrode is connected to the temperature acquisition circuit board through a wire, and the cutting edge of the diamond tool is arranged on the single crystal diamond layer.

[0009] The diamond tool device proposed in the present invention also has such a feature, wherein the single crystal diamond layer includes an upper single crystal diamond layer located on the upper surface of the boron-doped single crystal diamond layer and a lower single crystal diamond layer located on the lower surface of the boron-doped single crystal diamond layer, and the upper single crystal diamond layer, the boron-doped single crystal diamond layer and the lower single crystal diamond layer are synthesized in layers at one time by microwave plasma assisted chemical vapor deposition.

[0010] The diamond tool device proposed in the present invention also has such a feature, wherein the thicknesses of the upper single crystal diamond layer, the boron-doped single crystal diamond layer and the lower single crystal diamond layer are 300 μm, 200 μm and 500 μm respectively, and the three layers are connected through interatomic interactions generated by carbon-carbon chemical bonds, boron-carbon chemical bonds and boron-boron chemical bonds between the layer boundaries.

[0011] The diamond tool device proposed in the present invention also has the following feature: the boron doping concentration of the boron-doped single crystal diamond layer is 15 ppm.

[0012] The diamond tool device proposed in the present invention also has such a feature, and further includes: a bracket, used to install the diamond tool on the tool holder, and the diamond tool is brazed on the bracket; a ceramic tool support cover and a limit block are also provided on the bracket, and a Y-shaped groove for installing the electrode is opened on the limit block, and the ceramic tool support cover is covered on the top of the limit block; the ceramic tool support cover and the bracket are connected to the tool holder through a fixing member.

[0013] The diamond tool device proposed in the present invention also has the following characteristics: one end of the electrode is connected to the side of the diamond tool, and the other end is connected to the temperature collection circuit board through a silver wire. The electrode is formed by a balanced magnetron sputtering method and contains: a Mo electrode connected to the side of the boron-doped single crystal diamond layer, and an Au layer covering the surface of the Mo electrode.

[0014] The diamond tool device proposed in the present invention also has such a feature, wherein the tool holder also has a lower cover plate, which is located at the lower side of the main body, the upper cover plate and the main body, the lower cover plate and the main body are connected by connecting parts, and an installation cavity is opened inside the main body, and the temperature collection circuit board and the power supply are arranged in the installation cavity, and the temperature collection circuit board and the power supply are connected by a wire.

[0015] The diamond tool device proposed in the present invention also has such a feature, wherein the temperature acquisition circuit board is provided with several constant current source output interfaces with different values, all of which are electrically connected to the constant current source shift button, and the constant current source output value is adjusted by pressing the constant current source shift button.

[0016] The diamond tool device proposed in the present invention also has such a feature that an STM 32 processor module is provided on the temperature acquisition circuit board, and the collected temperature signal is transmitted wirelessly via Bluetooth between the processor module and the host computer, and the sampling frequency is 500 Hz.

[0017] The diamond tool device proposed in the present invention also has such a feature, wherein an LED display screen is arranged on the temperature acquisition circuit board, and a display slot for exposing the LED display screen is arranged on the upper cover plate, and the LED display screen is used to display the real-time temperature signal value, the remaining battery power and the current source input value.

[0018] Function and Effect of the Invention

[0019] According to the diamond tool device of the present invention, since the diamond tool has a boron-doped single-crystal diamond layer, its resistance changes with the change of temperature after being heated, so that it can sense the temperature of the cutting micro-area during operation, and can be used for online measurement of the temperature of the cutting area during single-point diamond turning processing; in addition, the diamond tool relies on the boron-doped single-crystal diamond layer as a temperature sensor. Compared with using the entire tool as a temperature sensor, the sensor size is significantly reduced, the heat capacity of the temperature sensor is effectively reduced, and the temperature response speed is significantly improved; and the cutting edge of the diamond tool is synthesized by single-crystal diamond that is not doped with boron, so when processing conductive materials, it does not affect the resistance value of the tool's temperature-sensitive layer, does not interfere with temperature measurement, and has a wider range of application scenarios.

[0020] Furthermore, the diamond tool of the present invention is synthesized in layers at one time by microwave plasma assisted chemical vapor deposition, so that the uniformity of boron doping is improved and the mechanical properties of the tool are enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the diamond tool device of the present invention.

[0022] Figure 2 It is a schematic diagram of the structural components of the diamond tool of the present invention.

[0023] Figure 3 It is a structural explosion diagram of the diamond tool device of the present invention.

[0024] Figure 4 It is a schematic diagram of the connection structure between the electrode and the diamond tool of the present invention.

[0025] Figure 5 It is an exploded view of the connection structure between the electrode and the diamond tool of the present invention.

[0026] Figure 6 It is a bottom view of the diamond tool device of the present invention.

[0027] Figure numerals: diamond tool device 10, diamond tool 1, electrode 11, silica gel block 111, boron-doped single crystal diamond layer 12, upper single crystal diamond layer 13, lower single crystal diamond layer 14, ceramic tool support cover 15, through holes 151, 61, limit block 16, Y-shaped groove 161, tool holder 2, main body 21, mounting cavity 211, mounting platform 212, mounting hole 213, upper cover plate 22, display slot 221, lower cover plate 23, fixing hole 231, temperature acquisition circuit board 3, power supply 4, constant current source shift button 5, bracket 6, fixing part 7, connecting part 8, LED display screen 9. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the diamond tool device of the present invention is specifically described below in conjunction with embodiments and drawings.

[0029] <Example>

[0030] Figure 1 It is a structural diagram of the diamond tool device of the present invention.

[0031] like Figure 1As shown, a diamond tool device 10 is used to cut a target object and measure the temperature of the cutting micro-area of ​​the target object online. It is mainly composed of two functional modules: a self-temperature-sensing diamond tool and a temperature acquisition part, specifically including a diamond tool 1, a tool holder 2 and a bracket 6. The diamond tool 1 is mounted on the bracket 6, and the bracket 6 is mounted on the tool holder 2, that is, the diamond tool 1 is mounted on the tool holder 2 through the bracket 6. The temperature acquisition part is mainly composed of two parts: a hardware circuit and a software host computer, which are responsible for the acquisition, conversion and transmission of the temperature signal sensed by the tool on the cutting micro-area.

[0032] Figure 2 It is a schematic diagram of the structural components of the diamond tool of the present invention.

[0033] like Figure 2 As shown, the diamond tool 1 has a boron-doped single crystal diamond layer 12 (also called a BDD layer) and a single crystal diamond layer (also called an SPD layer), and the single crystal diamond layer includes an upper single crystal diamond layer 13 located on the upper surface of the boron-doped single crystal diamond layer 12 and a lower single crystal diamond layer 14 located on the lower surface of the boron-doped single crystal diamond layer 12. The thicknesses of the upper single crystal diamond layer 13, the boron-doped single crystal diamond layer 12 and the lower single crystal diamond layer 14 are 300 μm, 200 μm and 500 μm respectively, and the three layers are bonded and connected through interatomic interactions generated by carbon-carbon chemical bonds, boron-carbon chemical bonds and boron-boron chemical bonds at the layer boundaries, and are synthesized in layers at one time by microwave plasma-assisted chemical vapor deposition, ensuring that the three-layer structure is connected through interatomic interactions to maintain the excellent mechanical properties of the diamond tool.

[0034] The boron-doped single crystal diamond layer 12 is a P-type semiconductor, which has a thermosensitive property. After being heated, its resistance changes with the temperature, so it can be used to sense the temperature of the cutting micro-area. The boron doping concentration of the boron-doped single crystal diamond layer 12 is 15ppm (B / C), and the diamond is synthesized in one layer by microwave plasma assisted chemical vapor deposition. The uniformity of boron doping is improved, and the mechanical properties of the tool are significantly improved.

[0035] The cutting edge of the diamond tool 1 is arranged on the single crystal diamond layer, which can be on the upper single crystal diamond layer 13 or on the lower single crystal diamond layer 14. The sensor of the diamond tool 1 is only the boron-doped single crystal diamond layer 12. Compared with the tool as a temperature sensor after being doped with boron as a whole, the sensor is small in size, which effectively reduces the heat capacity of the temperature sensor and significantly improves the temperature response speed. At the same time, the cutting edge of the diamond tool 1 is synthesized from single crystal diamond that is not doped with boron, so when processing conductive materials, it does not affect the resistance value of the tool's temperature-sensitive layer, does not interfere with temperature measurement, and has a wider range of application scenarios.

[0036] Figure 3It is a structural explosion diagram of the diamond tool device of the present invention.

[0037] like Figure 3 As shown, the tool holder 2 is made of ceramic, and has a body 21, an upper cover plate 22 and a lower cover plate 23. The body 21 is hollow to form an installation cavity 211. The installation cavity 211 is provided with a temperature acquisition circuit board 3 (i.e., the hardware circuit), a power supply 4, an LED display screen 9 and a constant current source shift button 5 connected by wires. The upper cover plate 22 is provided with a display slot 221 for the LED display screen 9 to be exposed and a mounting hole for installing the constant current source shift button 5. The LED display screen 9 is used to display the real-time temperature signal value, the remaining battery power and the current source input value. The temperature acquisition circuit board 3 is provided with an STM 32 processor module, and the collected temperature signal is transmitted between the processor module and the host computer via Bluetooth wireless transmission, wherein the sampling frequency is 500Hz. The upper cover plate 22 is covered on the upper side of the body 21, and the lower cover plate 23 is located on the lower side of the body 21. The upper cover plate 22 and the body 21, and the lower cover plate 23 and the body 21 are connected by a connector 8. In this embodiment, the connector 8 can be a cross screw.

[0038] like Figure 1 As shown, the diamond tool 1 is brazed on the bracket 6, the bracket 6 is made of ceramic and connected to the tool holder 2 through a fixing member 7. An electrode 11 is also provided on the side of the diamond tool 1, and the electrode 11 is a Mo-Au electrode formed by magnetron sputtering of the diamond tool through its side. The thickness of the Mo-Au electrode is 50nm / 100nm respectively, and it contains a Mo electrode and an Au layer. The Mo electrode is connected to the side of the boron-doped single crystal diamond layer 12, and the Au layer covers the surface of the Mo electrode to play an oxidation protection role.

[0039] Figure 4 It is a schematic diagram of the connection structure between the electrode and the diamond tool of the present invention.

[0040] Figure 5 It is an exploded view of the connection structure between the electrode and the diamond tool of the present invention.

[0041] like Figure 3-Figure 5 As shown, the installation structure of the electrode 11 is as follows: the electrode 11 has two pieces, which are symmetrically arranged on both sides of the diamond tool 1, one end of the electrode 11 is attached to the side of the diamond tool 1, and the other end is used to connect the silver wire, and the electrode 11 is connected to the temperature collection circuit board 3 through the silver wire. The bracket 6 is also provided with a limit block 16 for fixing the electrode 11, as shown in FIG. Figure 5As shown, a Y-shaped groove 161 is provided in the limit block 16, and two electrodes 11 are attached to the Y-shaped groove 161. A silicone block 111 is provided between the two electrodes 11 at one end close to the diamond tool 1, and the two electrodes 11 are connected together by the silicone block 111, and the silicone block 111 is located at the straight groove portion 1611 in the Y-shaped groove 161. One end of the body 21 of the tool holder 2 is recessed downward to form a mounting platform 212, and a mounting hole 213 is provided on the mounting platform 212. A ceramic tool support cover 15 is also provided above the diamond tool 1. The ceramic tool support cover 15 has a shape that matches the limit block 16, and is covered on the top of the limit block 16 during installation, so that the electrode 11 and the silver wire are not exposed to the working environment. The ceramic knife support cover 15 is fixed to the bracket 6 and the knife holder 2 through the fixing part 7. Specifically, the ceramic knife support cover 15 and the bracket 6 are respectively provided with a through hole 151 and 61 corresponding to each other. The fixing part 7 is a hexagon socket screw, which passes through the through holes 151, 61 and the mounting hole 213 on the mounting platform 212 in sequence and is fixed to the knife holder 2 body 21.

[0042] The diamond tool 1 is connected to the temperature acquisition circuit board 3 by connecting the silver wire through the Mo-Au electrode formed by magnetron sputtering on its side. Since the resistance value of the boron-doped single crystal diamond layer 12 of different temperature-sensitive diamond tools 1 is measured by the four-wire method, in order to balance the internal resistance heating of the boron-doped single crystal diamond layer 12 caused by different resistance values, the temperature acquisition circuit board 3 is provided with a number of constant current source output interfaces with different values, which are all electrically connected to the constant current source shift button 5, and the constant current source output value is adjusted by pressing the constant current source shift button 5. In this embodiment, three different output values ​​are set, namely 1μA, 5μA, and 10μA.

[0043] Figure 6 It is a bottom view of the diamond tool device of the present invention.

[0044] like Figure 6 As shown, a fixing hole 231 is also provided at the bottom of the lower cover plate 23 for connecting the entire diamond tool device with the ultra-precision machine tool.

[0045] The installation process of this example is as follows:

[0046] (1) Installation of the diamond tool 1: The hexagonal screws are passed through the through holes 151 and 61 on the ceramic tool support cover 15 and the bracket 6 respectively and are tightened and fixed to the screw holes on the tool holder 2, and the silver wire is soldered to the electrode 11 of the diamond tool 1.

[0047] (2) Connection of the temperature acquisition circuit board 3: The temperature acquisition circuit board 3 is placed inside the mounting cavity 211 of the tool holder 2 and connected to the silver wire led out of the diamond tool 1 to realize the connection between the diamond tool 1 and the temperature acquisition circuit board 3; in addition, the temperature acquisition circuit board 3 is also connected to the power supply 4 through a wire to realize the power supply 4 to supply power to the temperature acquisition circuit board 3.

[0048] (3) The diamond tool device is locked with the ultra-precision machine tool through the hexagonal screws and the fixing holes 231 at the bottom of the lower cover plate 23, thereby completing the fixed connection between the diamond tool device and the machine tool.

[0049] Embodiment Function and effect:

[0050] According to the diamond tool device of the above embodiment, since the diamond tool 1 has a boron-doped single crystal diamond layer 12, its resistance changes with the change of temperature after being heated, so that the temperature of the cutting micro-area can be sensed during the working process, and can be used for online measurement of the temperature of the cutting area during the single-point diamond turning process; in addition, the diamond tool 1 only relies on the boron-doped single crystal diamond layer 12 as a temperature sensor. Compared with using the tool as a whole as a temperature sensor, the sensor size is significantly reduced and the volume is small, which effectively reduces the heat capacity of the temperature sensor and significantly improves the temperature response speed; and the boundaries of the three-layer structure of the diamond tool are connected by atomic interactions generated by carbon-carbon chemical bonds, boron-carbon chemical bonds, and boron-boron chemical bonds. Therefore, the mechanical strength and wear resistance of the diamond tool are not significantly different from those of a pure diamond single crystal tool.

[0051] Furthermore, the cutting edge of the diamond tool 1 is synthesized from single crystal diamond that is not doped with boron, so when processing conductive materials, it does not affect the resistance value of the tool's temperature-sensitive layer, does not interfere with temperature measurement, and has a wider range of application scenarios.

[0052] Furthermore, the cutting temperature measurement method in the above embodiment utilizes the inherent thermal sensitivity of the boron-doped single crystal diamond layer 12 material of the tool, and realizes the perception of the temperature signal of the cutting area by collecting the real-time change of the resistance signal of the boron-doped diamond single crystal layer 12 after being heated during the cutting process. Different from the temperature-sensitive diamond tool that is prepared by high temperature and high pressure and is doped with boron as a whole, the diamond tool 1 in this patent is made by microwave plasma assisted chemical vapor deposition (MPCVD), and the crystal quality is more efficient and stable, the uniformity of boron doping is improved, and the mechanical properties of the tool are improved.

[0053] Furthermore, a Mo-Au electrode 11 is formed on the diamond tool 1 by a balanced magnetron sputtering method, and the Mo electrode is directly connected to the exposed boron-doped single crystal layer on the side of the diamond tool. Au covering the Mo electrode can play a good oxidation protection role.

[0054] The above embodiments are only used to illustrate specific implementation modes of the present invention, and the present invention is not limited to the description scope of the above embodiments.

Claims

1. A diamond tool device, characterized in that: The method is used for cutting a target object and measuring the temperature of a cutting micro-region of the target object online, comprising: Diamond tool (1), A tool holder (2) for mounting the diamond tool (1). Wherein, the diamond tool (1) has: Electrode (11); A boron-doped single crystal diamond layer (12), whose resistance changes with temperature after being heated, and is used to sense the temperature of the cutting micro-region; and A single crystal diamond layer is bonded to the boron-doped single crystal diamond layer (12) through interatomic interaction; The tool holder (2) has: The body (21) is provided with a temperature collection circuit board (3) and a power supply (4) inside. An upper cover plate (22) is arranged on the upper side of the body (21) and is provided with a constant current source shift button (5) electrically connected to the temperature collection circuit board (3); The electrode (11) is connected to the temperature collection circuit board (3) via a wire, and the cutting edge of the diamond tool (1) is arranged on the single crystal diamond layer; The single crystal diamond layer comprises an upper single crystal diamond layer (13) located on the upper surface of the boron-doped single crystal diamond layer (12) and a lower single crystal diamond layer (14) located on the lower surface of the boron-doped single crystal diamond layer (12). The upper single crystal diamond layer (13), the boron-doped single crystal diamond layer (12) and the lower single crystal diamond layer (14) are synthesized in layers at one time by microwave plasma assisted chemical vapor deposition.

2. The diamond tool device according to claim 1, characterized in that: in, The thicknesses of the upper single crystal diamond layer (13), the boron-doped single crystal diamond layer (12) and the lower single crystal diamond layer (14) are 300 μm, 200 μm and 500 μm respectively, and the three layers are connected to each other through interatomic interactions generated by carbon-carbon chemical bonds, boron-carbon chemical bonds and boron-boron chemical bonds at the boundaries between the layers.

3. The diamond tool device according to claim 1, characterized in that: in, The boron doping concentration of the boron-doped single crystal diamond layer (12) is 15 ppm.

4. The diamond tool device according to any one of claims 1 to 3, characterized in that: Also includes: A bracket (6) for mounting the diamond tool (1) on the tool holder (2), wherein the diamond tool (1) is brazed on the bracket (6); The bracket (6) is also provided with a ceramic knife support cover (15) and a limit block (16); the limit block (16) is provided with a Y-shaped groove (161) for mounting the electrode (11); and the ceramic knife support cover (15) is covered on the top of the limit block (16); The ceramic knife support cover (15) and the bracket (6) are connected to the knife holder (2) via a fixing member (7).

5. The diamond tool device according to claim 4, characterized in that: in, One end of the electrode (11) is connected to the side of the diamond tool (1), and the other end is connected to the temperature collection circuit board (3) through a silver wire. The electrode (11) is formed by a balanced magnetron sputtering method and comprises: A Mo electrode connected to the side of the boron-doped single crystal diamond layer (12), The Au layer covers the surface of the Mo electrode.

6. The diamond tool device according to claim 4, characterized in that: in, The tool holder (2) further comprises a lower cover plate (23) located at the lower side of the body (21); the upper cover plate (22) and the body (21), and the lower cover plate (23) and the body (21) are connected via a connecting piece (8). The body (21) is provided with an installation cavity (211) inside, the temperature collection circuit board (3) and the power supply (4) are arranged in the installation cavity (211), and the temperature collection circuit board (3) and the power supply (4) are connected via a wire.

7. The diamond tool device according to any one of claims 1 to 3, characterized in that: in, The temperature acquisition circuit board (3) is provided with a plurality of constant current source output interfaces with different values, all of which are electrically connected to the constant current source shift button (5), and the constant current source output value is adjusted by pressing the constant current source shift button (5).

8. The diamond tool device according to claim 7, characterized in that: in, The temperature collection circuit board (3) is provided with an STM 32 processor module, and the collected temperature signal is transmitted via Bluetooth wireless between the processor module and the host computer, with a sampling frequency of 500 Hz.

9. The diamond tool device according to claim 6, characterized in that: in, The temperature acquisition circuit board (3) is provided with an LED display screen (9), and the upper cover plate (22) is provided with a display slot (221) for exposing the LED display screen (9). The LED display screen (9) is used to display a real-time temperature signal value, a remaining battery charge, and a current source input value.

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